The present invention generally relates to seal assemblies, and more particularly, to an improved seal assembly for sealing a rotatable shaft protruding from a fluid-containing chamber in internal combustion engines and the like.
As is well known in the mechanical arts, seal assemblies can be used in a wide variety of structural and machine components having a part protruding from a fluid-containing chamber. For example, seal assemblies can be used in sealing rotatable shafts in internal combustion engines. Most commonly, this application entails sealing the camshaft, which is enclosed in the oil-containing head of the internal combustion engine, such that the camshaft can protrude from the head to, for example, engaging with the timing belt of an internal combustion engine. While such a seal assembly may take a variety of structural configurations, the typical seal assembly used for these purposes will include a removable saddle-shaped seal cap secured to a mating saddle-shaped main body so as to define an opening through which the rotatable shaft is mounted. Thus, the seal carrier provides for the installation and removal of a rotatable shaft, such as a camshaft in an internal combustion engine.
The most common method by which such seal assemblies are formed is to form the seal cap and corresponding main body separately by casting, forging or other similar techniques and thereafter, bolting or otherwise securing together the seal cap and the main body. In many instances, finish machining of the opening through which the rotatable shaft is mounted is completed after the initial assembly of these components. This manufacturing method requires numerous machining operations, as well as preliminary assembly and disassembly of the components prior to installation of the rotatable shaft, all of which significantly increase the manufacturing costs of the internal combustion engine.
Another method by which past seal assemblies have been produced involves forming the seal cap and the main body integrally and thereafter, separating these components by sawing or otherwise cutting away excess material provided to initially join the components. After separation of the seal cap and the main body, the connecting surfaces thereof must be machined which is very time-consuming and possesses limited tolerances. In that regard, the limited tolerances result in an imperfect match upon reconnection of the main body and the seal cap. As a result, oil may seep through such imperfections between the connected surfaces of the seal cap and the main body, thereby leading to degradation of the components in the internal engine within which the seal carrier is mounted. While the use of gaskets and/or additional machining have been used to minimize this problem, such techniques increase manufacturing time and costs and do not significantly minimize fluid leakage. Therefore, there is a need in the art for an improved seal assembly which effectively seals fluids, such as oil, in internal combustion engines without significantly adding to manufacturing costs.
While a few attempts in the art of split bearings have been made to facilitate alignment of bearings by using fracture techniques along fracture planes resulting in interlocking or mating rough surfaces that are capable of being reengaged, none of these attempts employ their fracture techniques in the art of seal assemblies for purposes of preventing fluid leaks, especially in internal combustion engines. For example, Fetouh, U.S. Pat. No. 4,684,267, employs a fracture technique to a split bearing assembly in an effort to facilitate alignment of the split bearing upon reengagement by reducing the amount of bending necessary for reengaging the bearing components. Fetouh, however, is totally unrelated to seal assemblies and provides no insight whatsoever as to the aforementioned problems associated with seal assemblies.
Accordingly, there is a need in the art for an improved seal assembly which is capable of sealing a rotatable shaft protruding from a fluid-containing chamber in an internal combustion engine. There is also a need in the art for a method by which such an improved seal assembly can be produced.